No. 1: b&w works relatively well here but there isn't really a clear composition and there aren't any leading lines. IMO the fencing and wires make it look a little messy composition-wise as well.
No. 2: nice composition but lighting is a little dull, would have looked nice using a long exposure time.
No. 3: the colours of the rock formations are nice, along with the rich blue sea, but there is no focus or direction in the composition. Try and employ the rule of thirds or pick out a particular object or landmark that draws the eye in.
No. 4: this would definitely be my favourite. Strong composition, nice lighting, well done.
Hope my comments helped!
